1. Technical Field of the Invention
The present invention relates to technology for analyzing a correlation between a time series of a plurality of notes (hereinafter, referred to as a ‘designated sequence of notes’) designated by a user and a piece of music.
2. Description of the Related Art
A technology for searching a plurality of pieces of music (hereinafter, referred to as ‘reference pieces of music’) for a target piece of music including a designated sequence of notes has been proposed. For example, non-patent reference 1 discloses a technology for computing an edit distance (Levenshtein distance) between a designated sequence of notes and a sequence of notes included in a reference piece of music (referred to as ‘reference sequence of notes’ hereinafter) as a similarity between the designated sequence of notes and the reference sequence of notes for each reference piece of music and searching for a reference piece of music (that is, a piece of music intended by a user) correlated with the designated sequence of notes on the basis of similarity of each reference piece of music.
[Non-Patent Reference 1] K. Lemstrom and E. Ukkonen, “Including Interval Encoding into Edit Distance Based Music Comparison and Retrieval”, Proc. AISB. 2000
A user sequentially designates notes of a designated sequence of notes by manipulating manipulators of an electronic musical instrument. It is possible to designate a chord as a designated sequence of notes by simultaneously manipulating a plurality of manipulators of the electronic musical instrument. However, although the user intends to simultaneously manipulate a plurality of manipulators, the manipulators are manipulated at different points of time in practice. Accordingly, even if the user designates the same chord, the order of tones of the chord may be changed. For example, though the user intends to designate a chord of “do, mi, so”, various note rows such as “do, so, mi”, “mi, do, so”, “so, do, mi”, etc. may be designated as designated sequences of notes. Accordingly, an error in the order of notes designated by the user affects a result of analysis of a similarity between a designated sequence of notes and a reference sequence of notes. While a case in which the order of tones of a chord is changed is considered in the above description, the order of notes may be changed according to user error.